This invention generally relates to golf balls, and more specifically, to a multi-component golf ball. In particular, this invention relates to a golf ball having a core, at least one cover layer, and one or more interior mantle layers disposed between the core and cover layer. Relatively small foam granules are dispersed throughout one or more of the mantle layers, the core, or both. The multi-component golf balls of the present invention, having such a configuration and using such foam granules, have been found to provide the distance and durability characteristics approaching that of a conventional two-piece ball while also providing the xe2x80x9cclick and feelxe2x80x9d of a conventional three-piece or xe2x80x9cwoundxe2x80x9d ball.
Conventional golf balls can be divided into two general types or groups, two-piece balls or wound balls (also known as three-piece balls). The difference in play characteristics resulting from these different types of constructions can be quite significant.
Balls having a two-piece construction are generally most popular with the average recreational golfer because they provide a very durable ball while also providing maximum distance. Two-piece balls are made with a single solid core, usually made of a crosslinked rubber, which is encased by a cover material. Typically, the solid core is made of polybutadiene which is chemically crosslinked tough, cut-proof blended cover. The cover is generally material such as SURLYN(copyright), which is a trademark for an ionomer resin produced by DuPont. The combination of the core and cover materials provide a xe2x80x9chardxe2x80x9d ball that is virtually indestructible by golfers. Further, such a combination imparts a high initial velocity to the ball which results in improved distance. Because these materials are very rigid, two piece balls have a hard xe2x80x9cfeelxe2x80x9d when struck with a club. Likewise, due to their hardness, these balls have a relatively low spin rate which makes them difficult to control, particularly in shorter approach shots. However, as golf ball manufacturers continue to improve the spin and feel characteristics of the two-piece ball, it is likely that the two-piece ball will continue to grow in popularity.
But, at the present time, the wound ball remains the preferred ball of the more advanced players due to its superior spin and feel characteristics. Wound balls typically have either a solid rubber or liquid center core around which many yards of a stretched elastic thread or yarn are wound. The wound core is then covered with a durable cover material such as a SURLYN(copyright) or similar material or a softer cover such as Balata. Wound balls are generally softer and provide more spin, which enables a skilled golfer to have more control over the ball""s flight. However, wound higher spinning balls typically have a shorter distance as compared to a two-piece ball. Moreover, as a result of their more complex structure, wound balls generally require a longer time to manufacture and are more expensive to produce than a two-piece ball.
Consequently, a need exists for an improved ball which provides the xe2x80x9cclick and feelxe2x80x9d of a wound ball, while also providing the relative ease of manufacturing, durability and distance of a two-piece ball.
Several patents have been issued which are directed toward modifying the properties of a conventional two-piece ball by altering the typical single-layer core and single cover layer construction to provide a multi-layer core. The developments disclosed in the prior art patents are directed toward improving a variety of golf ball characteristics.
Several patents are directed toward improving the carry distance of ball having improved rebound characteristics in order to increase its flight distance. This golf ball has a center portion and an outer layer formed from a rubber composition, preferably having a base rubber of polybutadiene, wherein the outer layer further contains a gravity filler such as tungsten or tungsten carbide so as to impart a higher specific gravity to the outer layer than that of the inner layer. The difference in specific gravity of the layers should be 0.15-0.8 for small balls and 0.15-0.45 for large balls. Preferably, the outer layer is harder than the center portion.
U.S. Pat. No. 5,184,828 relates to a solid three-piece golf ball having improved rebound characteristics and carry distance while maintaining an adequate spin rate. These characteristics are obtained by controlling the size of the inner core and outer layer as well as the specific gravity and hardness. The core and mantle layers are made from a rubber compound such as polybutadiene, and have a Shore D hardness of 30-62 and 30-56, respectively. The key to obtaining the desired rebound characteristics is that the maximum hardness (42-62) must be located at the interface between the core and the mantle and the hardness must then decrease both inwardly and outwardly.
U.S. Pat. No. 4,714,253 is also directed toward a three-piece golf ball having an excellent rebound coefficient. This golf ball has a core with a Shore C hardness of 57-80 in its center, but not more than 83 at a distance between 5-10 mm from its center and outer layer with a Shore C hardness of 70-83.
Additionally, there are a number of patents also directed toward improving the spin, click or feel of solid balls while maintaining the distance provided by the solid construction. A variety of approaches to manipulating the core construction are described in the art. For example, U.S. Pat. No. 5,072,944 discloses a three-piece solid golf ball having a center and outer layer which are prepared from a rubber composition, preferably having a base rubber of polybutadiene. It is desirable that the center core is softer than the outer layer, each having a hardness (Shore C) of 25-50 and 70-90, respectively.
U.S. Pat. No. 4,625,964 relates to a solid golf ball having a polybutadiene rubber core of a diameter not more than 32 mm, and a polybutadiene rubber intermediate layer having a specific gravity of lower than that
U.S. Pat. No. 4,650,193 is directed toward a solid golf ball having a core comprising a central portion and an integral outer layer. Preferably, the core is a curable elastomer such as polybutadiene which is treated with a cure altering agent to soften an outer layer of the core, thereby producing a central layer with a hardness (Shore C) of greater than 75 and an outer layer with a hardness (Shore A) of less than 80.
U.S. Pat. No. 4,848,770 discloses a non-wound, three-piece golf ball which includes a core of a highly filled synthetic rubber or polymeric material, an intermediate mantle of an unfilled synthetic rubber and a cover. The core and intermediate mantle have a hardness of between 50-95.
U.S. Pat. No. 5,002,281 is directed toward a three-piece solid golf ball which has an inner core having a hardness of 25-70 (Shore C), an outer shell having a hardness of 80-95 (Shore C) and a cover. Further, the specific gravity of the inner core must be greater than 1.0, but less than or equal to that of the outer shell, which must be less than 1.3.
U.S. Pat. No. 5,253,871 concerns a golf ball having a three-piece structure comprising an elastomer core, an intermediate layer of a thermoplastic material containing at least 10% of ether block copolymer, preferably blended with an ionomer and a thermoplastic cover.
Further, there are also several patents which are directed to golf balls having multiple cover layers. For example, U.S. Pat. No. 4,431,193 relates to a golf ball having a multi-layer cover wherein the inner layer is a hard, high flexural modulus ionomer resin and the outer layer is a soft, low flexural modulus ionomer resin, and wherein either or both layers may comprise a foamed ionomer resin.
U.S. Pat. No. 5,314,187 also relates to golf balls having a multiple layer cover, wherein the outer layer is molded over the inner layer and comprises a blend of balata and an elastomer and the inner layer is an ionomer resin.
U.S. Pat. No. 4,919,434 is directed toward a golf ball having a cover which comprises an inner layer and an outer layer each of which comprise a thermoplastic resin. Preferably the layers comprise materials that are capable of fusion bonding with each other.
Prior artisans have attempted to incorporate metal layers or metal the balls. For example, U.S. Pat. No. 3,031,194 to Strayer is directed to the use of a spherical inner metal layer that is bonded or otherwise adhered to a resilient inner constituent within the ball. The ball utilizes a liquid filled core. U.S. Pat. No. 4,863,167 to Matsuki, et al. describes golf balls containing a gravity filler which may be formed from one or more metals disposed within a solid rubber-based core. U.S. Pat. Nos. 4,886,275 and 4,995,613, both to Walker, disclose golf balls having a dense metal-containing core. U.S. Pat. No. 4,943,055 to Corley is directed to a weighted warmup ball having a metal center.
Prior artisans have also described golf balls having one or more interior layers formed from a metal, and which feature a hollow center. Davis disclosed a golf ball comprising a spherical steel shell having a hollow air-filled center in U.S. Pat. No. 697,816. Kempshall received numerous patents directed to golf balls having metal inner layers and hollow interiors, such as U.S. Pat. Nos. 704,748; 704,838; 713,772; and 739,753. In U.S. Pat. Nos. 1,182,604 and 1,182,605, Wadsworth described golf balls utilizing concentric spherical shells formed from tempered steel. U.S. Pat. No. 1,568,514 to Lewis describes several embodiments for a golf ball, one of which utilizes multiple steel shells disposed within the ball, and which provide a hollow center for the ball.
As to the incorporation of glass or vitreous materials in golf balls, U.S. Pat. No. 985,741 to Harvey discloses the use of a glass shell. Other artisans described incorporating glass microspheres within a golf ball such as in U.S. Pat. No. 4,085,937 to Schenk.
In contrast, the use of polymeric materials in intermediate layers within a golf ball, is more popular than, for instance, the use of glass or other vitreous material. Kempshall disclosed the use of an interior coating layer of plastic in U.S. Pat. Nos. 696,887 and 701,741. Kempshall further described incorporating a fabric layer in conjunction with a plastic layer in U.S. Pat. Nos. 696,891 and 700,656. Numerous subsequent approaches were patented in which a plastic inner layer was incorporated in a golf ball. A thermoplastic outer core layer was disclosed in U.S. Pat. No. 3,534,965 to Harrison. Inner synthetic polymeric layers are noted in U.S. Pat. No. 4,431,193 to Nesbitt. An inner layer of thermoplastic material surrounding a core is described in U.S. Pat. No. thermoplastic is disclosed in U.S. Pat. No. 5,253,871 to Viellaz. Golf balls with thermoplastic interior shell layers are described in U.S. Pat. No. 5,480,155 to Molitor, et al.
Although satisfactory in many respects, these patents are not specifically directed to the use of a particular configuration of foamed material dispersed within a particular type of polymeric material as utilized in the present invention and described herein.
Prior artisans have attempted to incorporate various particles and filler materials into golf ball cores and intermediate layers. U.S. Pat. No. 3,218,075 to Shakespeare discloses a core of fiberglass particles dispersed within an epoxy matrix. Similarly, U.S. Pat. No. 3,671,477 to Nesbitt discloses an epoxy-based composition containing a wide array of fillers. A rubber intermediate layer containing various metal fillers is noted in U.S. Pat. No. 4,863,167 to Matsuki, et al. Similarly, a rubber inner layer having filler materials is noted in U.S. Pat. No. 5,048,838 to Chikaraishi, et al. More recently, a golf ball with an inner layer of reinforced carbon graphite is disclosed in U.S. Pat. No. 5,273,286 to Sun.
However, none of these patents disclose a multi-layer ball having the materials and material property requirements as disclosed herein to provide the improved golf balls of the present invention.
In view of the ever increasing demands of the current golf industry, there exists a need for yet another improved golf ball design and construction. Specifically, there is a need for a golf ball that exhibits a high initial velocity or coefficient of restitution (COR), may be driven relatively long distances in regulation play, and which may be readily and inexpensively manufactured. And, there is a need for such a golf ball that further exhibits desirable xe2x80x9cclick and feelxe2x80x9d characteristics.
These and other objects and features of the invention will be apparent from the following summary and description of the invention, the drawings, and from the claims.
The present invention is directed toward, in a first aspect, a golf ball comprising a core, a cover assembly disposed about the core, and a mantle layer disposed about the core, between the core and the cover layer. The mantle layer comprises a polymeric matrix material and a plurality of foam granules dispersed within the polymeric matrix material. The granules have a mean diameter of from about 0.001 inches to about 0.200 inches. The cover assembly may include one or more cover layers.
In yet another aspect, the present invention provides a golf ball comprising a core, a cover layer disposed about the core, and an interior mantle layer surrounding the core and disposed between the core and the cover layer. The mantle layer comprises a plurality of foam particles dispersed within a polymeric matrix material. The particles comprise one or more materials selected from a specific set of materials. The cover may be of a single or multi-layer configuration.
In yet a further aspect, the present invention provides a golf ball comprising a core, a cover layer disposed about the core, and an interior primary mantle surrounding the core and disposed between the core and the cover layer. The primary mantle includes a matrix material and a plurality of foam granules dispersed within the matrix material. The weight ratio of the granules to the matrix material is in a range of from about 10 to 95% of the matrix material to about 5 to 90% of the granules. The cover may include one or more cover layers.
In another aspect, the present invention provides a golf ball comprising a core, at least one cover layer disposed about the core, and a plurality of foam granules dispersed in the core. The foam granules have a mean diameter of from about 0.001 inches to about 0.200 inches.
In an additional aspect, the present invention provides a golf ball comprising a core, at least one cover layer disposed about the core, an interior mantle layer surrounding the core and disposed between said core and said cover, and a plurality of foam particles dispersed within either or both the core and the mantle layer. The foam particles are formed from one or more specific classes of materials.